Presentation is loading. Please wait.

Presentation is loading. Please wait.

Research in DBA? Josu de la Fuente St Mary’s Hospital Imperial College London.

Similar presentations


Presentation on theme: "Research in DBA? Josu de la Fuente St Mary’s Hospital Imperial College London."— Presentation transcript:

1 Research in DBA? Josu de la Fuente St Mary’s Hospital Imperial College London

2 A Genome-wide Approach to Investigate the Mechanism of Glucocorticoid Effect on Erythroid Progenitors in Diamond-Blackfan Anaemia. Leukaemia & Lymphoma Research November 2012 Value: £221,922 Investigation of the cellular and molecular pathogenesis of Diamond Blackfan Anaemia DD McPhail Charitable Settlement 2011 Value: £35,000 Development of a next generation sequencing-based test for genetic diagnosis in Diamond-Blackfan Anaemia NGS Award, Imperial College London April 2011 Value: £30,000

3 Male cell in bone marrow before culture Vimentin+ male cell Male cell in bone marrow adherent culture CD45+ male cell Katharine Evans 1, Robert Goldin 2 and Josu de la Fuente 1,3 1 Division of Haematology, Imperial College London London, 2 Division of Histopathology, Imperial College London and 3 Division of Paediatrics, St. Mary’s Hospital, London, United Kingdom Y Y XY-FISH Diamond Blackfan Anaemia Patients Have a Higher Rate of Hepatic Iron Accumulation than Thalassaemia Major Patients Leading to Fibrosis Background and Aims Diamond Blackfan anaemia is an inherited bone marrow failure syndrome with haematological and systemic manifestations. The classical presentation of the condition is the development of anaemia in infancy, which occurs in approximately 85-90% of the patients. Long-term 40% require transfusions as they fail to maintain erythropoiesis at acceptable doses of steroids and only approximately 10% of the patients go into remission. In the cohort of 64 patients who attend the specialist DBA clinic at St. Mary’s Hospital, London, we have identified that iron overload is a significant clinical problem, even when receiving adequate chelation treatment with current guidelines and at a young age (Poster #1268). Methods To investigate the iron load caused by transfusions and its effect we studied the liver biopsies of 13 patients with DBA and compared them with 27 patients suffering from thalassaemia major (TM) (Table 1). The findings were correlated with the number of transfusions, chelation treatment, ferritin level and MR techniques. Image analysis of the degree of fibrosis was performed using NIS-elements software after staining liver biopsy slides with Sirius Red (Figure 1). Results TM patients were significantly older [median age: TM 9 years (3-18), DBA 5 years (1-15); p=0.004], which was also reflected in the duration (months) of transfusion [TM 105 (12-198), DBA 52 (12-130); p=0.004]. However, there was no difference in the frequency of transfusions (p = 0.51) and in the length of time (months) between starting transfusions and chelation (TM 19, DBA 27; p=0.08). DBA patients received proportionately more chelation per transfusion than TM patients at the time of biopsy (proportion of chelation time to transfusion time: TM 1.24, DBA 1.58; p=0.015). Ferritin levels were higher in TM patients, though not significant [TM 2028  g/L ( ), DBA 1324  g/L ( ); p=0.16]. Despite having significantly fewer transfusions, the grade of iron deposition was higher in the DBA group (TM 2, DBA 3; p=0.035). This was also reflected in MRI T2* quantitation, which demonstrated a higher hepatic iron load in DBA patients [TM 3 ms (1-12), DBA 2 ms (1-3); p=0.59]. The rate of biochemical iron accumulation (mg/g DW) for every month of transfusion was significantly higher in the DBA group (TM 0.05, DBA 0.11; p=0.005). The rate of fibrosis accumulation was 60% higher in the DBA group, although this was not statistically significant (TM 0.1, DBA 0.16; p = 0.07) and could be due to a time lag between iron accumulation and fibrosis formation, particularly as the DBA patients were younger and had had shorter follow up (Table 2). Biochemical iron, ferritin level and MRI T2* had low, significant correlations with fibrosis in TM patients (0.547, p=0.001; 0.357, p=0.033; , p=0.011, respectively) and FerriScan in DBA patients (0.75, p=0.05) (Table 3). Conclusion In conclusion, DBA patients have a higher rate of iron accumulation with a trend to higher hepatic fibrosis. Table 1. Patient characteristics TM patients were significantly older and had received blood transfusions for a longer period of time reflecting the different referral pattern for both diseases to our institution. TM patients are referred for specialist advice of chelation treatment and consideration of bone marrow transplantation. DBA patients attend the specialist DBA clinic (n=64) from the moment of confirmation or strong suspicion of diagnosis. However, DBA patients received proportionately more chelation per transfusion than TM patients at the time of biopsy. Figure 1. Fibrosis image analysis using NIS-elements software Image analysis was performed using NIS-element software. Slides stained with Sirius Red were photographed using the software at a magnification of 4x/0.10. The software was programmed to differentiate background (white), hepatocytes (yellow) and collagen (red) and the percentage of the are representing collagen was calculated. Beta Thalassemia major Median (range) Diamond Blackfan anaemia Median (range) P value Number3615- Age (years)9 (3-18)5 (1-15)0.004 Sex (% male) Frequency of transfusions (weeks)4 (2-5)4 (2-6)0.51 Duration of transfusion (months)105 (12-198)52 (12-130)0.004 Duration of chelation (months)71 (0-183)16 (0-123)0.016 Table 2. Rate of iron and fibrosis accumulation in TM and DBA The rate of iron accumulation for every month of transfusion was significantly higher in DBA patients in comparison with patients with TM and there was a trend towards greater and fibrosis formation. Table 3. Correlation between iron accumulation measured by different techniques and fibrosis formation in TM and DBA Biochemical iron, ferritin level and MRI T2* had low, significant correlations with fibrosis in TM patients and FerriScan in DBA patients. Beta thalassemia MajorDiamond Blackfan Anaemia CorrelationP-valueCorrelationP-value Biochemical Iron (mg/g DW) Ferritin (μg/L) T2* liver ( ms ) Ferriscan (mg/g DW)

4 Male cell in bone marrow before culture Vimentin+ male cell Male cell in bone marrow adherent culture CD45+ male cell Josu de la Fuente 1,2, Yvonne Harrington 1, Sonia Bonanomi 1 1 Division of Paediatrics, St. Mary’s Hospital, London and 2 Centre for Haematology, Imperial College London, United Kingdom Y Y XY-FISH Iron Load Can Be Severe and Presents Early in DBA Patients Even When Receiving Adequate Chelation Treatment Background and Aims Diamond Blackfan anaemia is an inherited bone marrow failure syndrome with haematological and systemic manifestations. The classical presentation of the condition is development of anaemia in infancy which occurs in approximately 85-90% of the patients. Long-term 40% require transfusions as they fail to maintain erythropoiesis at acceptable doses of steroids and as approximately only 10% of the patients go into remission. Historical data has shown that transfusion dependent patients are at risk of significant morbidity and mortality and there is evidence that despite of adequate chelation treatment, they have significantly higher iron load than other transfusion dependent anaemias. Methods Fifty nine patients with clinical and laboratory features consistent with Diamond Blackfan anaemia attend the specialist DBA clinic at St. Mary’s Hospital (Table 1).Thirty-five patients (59.3%) had systemic features [the heart was involved in 17 patients (27.1%)], 7 patients (11.8%) had short stature only and 17 patients (28.8%) no systemic abnormalities. We have identified a ribosomal protein gene mutation in 18 patients with a novel approach [Abstract #2369]. Twenty-nine patients are transfusion dependent, 11 steroid responsive, 7 are in remission, 9 have undergone a bone marrow transplant achieving normal haemopoiesis and 3 have never developed anaemia of sufficient severity to warrant treatment. Three have deceased (two transfusion dependent patients due to overwhelming sepsis and one following unrelated bone marrow transplantation). Twenty two transfusion dependent patients have initiated chelation treatment: 19 patients (82.5%) are currently taking deferasirox and 3 (13.6%) continuous intravenous desferrioxamine as intensification treatment. Transfusion dependent patients have had their iron load assessed by a combination of techniques: ferritin, MRI T2*, FerriScan and liver biopsy (Table 2). Results Seventeen patients had severe hepatic iron load (LIC > 10 mg/g DW, maximum 38.6 mg/g DW): four before initiation of chelation treatment, 8 following chelation with desferrioxamine and 5 following deferasirox treatment. Seven of the patients had severe hepatic iron load (maximum mg/g DW) despite of maintaining the ferritin < 1500  g/L with adequate chelation treatment following guidelines for thalassaemia (Figure 1). Severe hepatic iron load was seen as early as in the second year of life (2 years 6 months LIC 38.6 mg/g DW). In patients with severe hepatic iron load, significant reductions achieved with chelation treatment as measured by liver biopsy or FerriScan were not reflected in an increase in T2* measurement until the treatment was advanced. In addition, FerriScan showed higher LIC values than liver biopsy in keeping with its ability to provide an overall measurement not affected by fibrosis. Three patients had cardiac iron load (T2* < 20 ms) in childhood, including 2 below the age of 6 years. Seven patients required intensification of chelation with continuous intravenous desferrioxamine, which was successful in all but one despite of the use of 50 mg/kg/day. Conclusion In summary, iron overload is a significant clinical problem in patients with DBA, even when receiving adequate chelation treatment with current guidelines and at a young age. It cannot be recognised by measurement of ferritin only and it requires an algorithm that uses all available techniques in an age appropriate manner from two years of age for its detection and management. Table 2. Assessment of iron load in transfusion dependent patients Transfusion dependent patients monitored with ferritin, MRI T2* and FerriScan Table 1. Patient characteristics of Imperial College Healthcare DBA Cohort. Age of presentation, treatment and chelation of DBA patients attending specialist DBA Clinic at St. Mary’s Hospital in London. Figure 2. Relationship between ferritin and LIC in patients with severe hepatic iron load Ferritin (  g/L) in X axis and FerriScan or liver biopsy LIC (mg/g DW) in Y axis Age at presentation n=59 in utero23.3% weeks3661% >3 -12 months1220.3% 1-5 years610.1% 5-10 years23.4% years00% >18 years11.6% Treatment Transfusions2949.1% Steroids1118.6% Remission711.8% No treatment35% BMT813.5% Deceased35% Chelation desferrioxamine313.6% deferasirox1982.5% Patient Age years Ferritin  g/L T2* heart ms T2* liver ms FerriScan mg/g DW Liver biopsy LIC mg/g DW

5 Patients with Diamond Blackfan Anaemia have abnormalities of cellular and humoral immunity Deena ISKANDER 1, Yvonne HARRINGTON 2, Irene ROBERTS 1,2, Anastasios KARADIMITRIS 1, Josu DE LA FUENTE 1,2. 1.Centre for Haematology, Imperial College, London, UK. 2.Department of Paediatrics, Imperial College Healthcare NHS Trust, London, UK. Introduction Diamond Blackfan Anaemia (DBA) is an inherited bone marrow failure syndrome characterised by anaemia, physical anomalies and an increased risk of malignancy. Although the hallmark of DBA is anaemia due to pure red cell aplasia, some patients exhibit additional cytopaenias, suggestive of a more widespread defect in haemopoiesis. In addition, aberrant immunity has been reported 1, but the scope and precise nature of these immunological defects is yet to be elucidated. Patient characteristics Table 1. Characteristics of patients with DBA at Imperial College Healthcare Trust. Conclusions  Infections are a major cause of mortality and morbidity in DBA.  This is the first report detailing immunological defects in DBA.  Combined deficiencies in lymphocyte subsets and immunoglobulins, alongside clinical infections, are present in 5/37 (13.5%) patients.  Suboptimal responses to vaccination are observed in many patients.  Further work should explore mechanisms underlying the observed defects and correlation between genotype and immunological phenotype.. References Fifty-nine patients with clinical and laboratory features consistent with DBA attend the specialist clinic at St. Mary’s Hospital, London. Their characteristics are summarised in table 1. Immunological parameters were available for 37 of the patients. At the time of inclusion in the study, all patients were alive and the median age was 7.8 years (range 18 months to 40.4 years). Acknowledgements Figure 1: History of infections in 37 patients with DBA. Results I. Infections are common in patients with DBA Sepsis was the cause of death in 2/3 patients with DBA who died - immunological investigations had not been performed prior to death in these cases. In 3 of the 37 patients investigated, a severe but non-fatal septic episode was reported: Salmonella gastroenteritis, Clostridium difficile colitis and neonatal pneumonia. Recurrent infections occurred in an additional 13 patients: respiratory 7/16 (54%), multisystem 3/16 (23%), otitis media 2/6 (15%) and urinary 1/37 (8%). 2 of the 16 patients with infections had longstanding neutropaenia and another 2 patients were receiving corticosteroids, but at low doses (0.15 and 0.12 mg/kg od). Median age (range)8.8 yrs ( ) Age at presentation In utero2/59 (3.3%) 0-12 wks36/59 (61%) 3-12 mo12/59 (20.3%) 1-5 yrs6/59 (10.1%) 5-10 yrs2/59 (3.4%) >18 yrs1/59 (1.6%) Systemic abnormalities All35/59 (59.3%) Cardiac17/59 (28.8%) Short stature7/59 (11.8%) The male to female ratio was 1.1:1 and patients were from a broad range of ethnic backgrounds. A ribosomal protein gene mutation was known in 18/37 (48.6%) patients. Of the 37 patients, 5 were in remission, 20 transfusion-dependent, 9 steroid- responsive, 2 managed with both steroids and blood transfusions and 1 treated with allogeneic stem cell transplantation (immunological investigations were undertaken pre-transplant). Methods Clinical information was obtained retrospectively from patients’ medical records and from the Imperial College Healthcare Trust electronic data system. Lymphocyte subsets were characterised by flow cytometry and age-specific normal ranges were defined as previously described. 2 Serology to identify antibodies against specific pathogens was performed using Enzyme-Linked Immunosorbent Assays. Figure 2 and table 2: Lymphocyte abnormalities in patients with DBA II. B lymphocyte deficiency is the most commonly detected immune abnormality Consistent lymphopaenia was found in 7/37 (18.9%) patients, unaccounted for by concurrent medical conditions or drug therapy. Abnormalities in one or more subsets were identified in the 7 patients with low total lymphocyte counts and in a further 10 patients with normal total lymphocytes counts. A low B lymphocyte fraction was the most frequent abnormality, present in 12/37 (32.4%) patients (figure 2 and table 2). III. Reduced immunoglobulins occur in patients with DBA Four of the 12 patients with reduced B lymphocytes also exhibited a defect in immunoglobulins (IgM and IgG 2 deficiency in 1, IgG 3 deficiency in 3). In total, low levels of at least 1 Ig isotype were detected in 4/34 (11.8%) patients. An additional 5/32 (15.6%) patients showed a selective deficiency in 1 of the 4 IgG subclasses. Importantly, these abnormalities were masked by normal total IgG levels. IV. Patients with DBA have suboptimal responses to vaccination A defect in lymphocytes and/or Igs was detected in 10/16 (62.5%) patients with infections. Conversely, in 9/21 (42.9%) patients, immune defects were observed in the absence of a history of infections. V. Immune defects may be subclinical Lymphocyte subset No. deficient patients (%) [total patients n = 37] Median of deficiency % of lower limit of normal for age (range) CD45+ total lymphocytes (low side scatter)7 (18.9)84 ( ) CD3+ T lymphocytes4 (10.8)59.7 ( ) CD56+ NK cells8 (21.2)75.5 ( ) CD19+ B lymphocytes12 (32.4)75 ( ) Corticosteroid therapy in DBA is delayed beyond infancy to allow administration of routine immunisations including measles, mumps and rubella (MMR) and H. Influenza type b (Hib) and minimise musculoskeletal side effects. We investigated specific antibodies against these pathogens as a marker for immunity 3, as shown in figure 3. Measurements were performed at varying time points post- vaccination, but there was no correlation between age and response. Figure 3: Immunity post-vaccination, indicated by unequivocally positive IgG against MMR and by Hib antibody titres. M MR Hi b n=23n=30 n=37

6 Target Enrichment and High-Throughput Sequencing of 80 Ribosomal Protein Genes to Identify Mutations Associated with Diamond-Blackfan Anaemia Gareth Gerrard 1 *, Mikel Valgañón 1, Hui En Foong 1, Dalia Kasperaviciute 2, Deena Iskander 1, Laurence Game 3, Michael Müller 2, Irene Roberts 1, Timothy J Aitman 2, Letizia Foroni 1, Josu de la Fuente 1, Anastasios Karadimitris 1 1 Centre for Haematology, Faculty of Medicine, Imperial College London, UK; 2 Imperial NIHR Biomedical Research Centre, Imperial College London, UK; 3 Genomics Laboratory, Clinical Sciences Centre, Imperial College London, UK. Work funded by AHSC/IHBRC Abstract Diamond-Blackfan anaemia (DBA) is a rare congenital stem cell disorder associated with inactivating mutations in ribosomal protein (RP) genes, causing defects in erythroid progenitor and precursor cell development. Of the 80 or so RP genes, loss of function mutations in 10 have been definitively associated with DBA. We used high-throughput sequencing to screen all 80 RP genes in 20 DBA patient samples (3 of which were controls) and found loss-of-function mutations in 15/17 (88.2%) of the test samples. Abstract Diamond-Blackfan anaemia (DBA) is a rare congenital stem cell disorder associated with inactivating mutations in ribosomal protein (RP) genes, causing defects in erythroid progenitor and precursor cell development. Of the 80 or so RP genes, loss of function mutations in 10 have been definitively associated with DBA. We used high-throughput sequencing to screen all 80 RP genes in 20 DBA patient samples (3 of which were controls) and found loss-of-function mutations in 15/17 (88.2%) of the test samples. Results Loss of function mutations were detected in RP genes in 17 of the 20 samples, including the 2 positive controls (Table 1). Of the 3 where no definitive mutation was seen, 1 was an unaffected sibling. All mutations were in RP genes previous described as being involved in DBA, although 7 affected novel codons. No verifiable large deletions/insertions were seen. FastQC indicated good quality sequencing metrics and all variations were subsequently validated by Sanger sequencing. Results Loss of function mutations were detected in RP genes in 17 of the 20 samples, including the 2 positive controls (Table 1). Of the 3 where no definitive mutation was seen, 1 was an unaffected sibling. All mutations were in RP genes previous described as being involved in DBA, although 7 affected novel codons. No verifiable large deletions/insertions were seen. FastQC indicated good quality sequencing metrics and all variations were subsequently validated by Sanger sequencing. Summary Using custom designed target enrichment and high-throughput benchtop sequencing technology, mutations were found in 17/20 samples and of the 17 test samples, 15 were found to have mutations in RP genes associated with DBA (88.2%). Consequently, we are now optimising this approach for use as our primary screening platform. Summary Using custom designed target enrichment and high-throughput benchtop sequencing technology, mutations were found in 17/20 samples and of the 17 test samples, 15 were found to have mutations in RP genes associated with DBA (88.2%). Consequently, we are now optimising this approach for use as our primary screening platform. Introduction Single nucleotide variations (SNV), small inversions/deletions (indels) and copy number variations (CNV) have been found in 10 RP genes in 25-35% of DBA patients, meaning that around 40% have no identifiable mutations (at least by conventional screening). However, given that all mutations in DBA characterised so far (with the exception of 2 cases with GATA1 mutations) affect RP genes, it is likely that mutations in one of the 80 RP genes will be eventually identified in a significant proportion of patients. Current screening methods are based on Sanger sequencing on a per-exon/per-gene basis, with the associated time, labour and cost restrictions. We therefore aimed to evaluate high- throughput sequencing technology, including a bespoke target enrichment platform, to screen all 80 known RP genes to facilitate rapid, cost-effective identification of DBA associated mutations (Figure 1). Introduction Single nucleotide variations (SNV), small inversions/deletions (indels) and copy number variations (CNV) have been found in 10 RP genes in 25-35% of DBA patients, meaning that around 40% have no identifiable mutations (at least by conventional screening). However, given that all mutations in DBA characterised so far (with the exception of 2 cases with GATA1 mutations) affect RP genes, it is likely that mutations in one of the 80 RP genes will be eventually identified in a significant proportion of patients. Current screening methods are based on Sanger sequencing on a per-exon/per-gene basis, with the associated time, labour and cost restrictions. We therefore aimed to evaluate high- throughput sequencing technology, including a bespoke target enrichment platform, to screen all 80 known RP genes to facilitate rapid, cost-effective identification of DBA associated mutations (Figure 1). FIGURE 1 Target enrichment (Agilent SureSelect) and High- Throughput Sequencing (Illumina MiSeq) workflow for the screening of all 80 ribosomal protein genes in patients with DBA Methods The coordinates for all 80 RP genes were used to generate custom SureSelect hybridisation capture baits via the Agilent web portal. 3µg DNA was extracted from 20 PB samples (including 2 controls with known mutations; 6 members from 3 family groups: a mother-daughter pair, a sibling pair and another sibling pair where one sibling was non-DBA and included as a control). Covaris sonication was performed and the DNA fragments were hybridised with the capture baits for 48h. After barcoded adapter ligation, the libraries were quantitated by qPCR and pooled into 2 runs of 10. The sequencing was performed on an Illumina MiSeq using 150bp paired-end chemistry. The reads were aligned to the hg19 reference using BWA and the variant calls made using GATK; ANNOVAR was used for functional annotations of the variants. Pipelines for both SNVs/indels and large deletions/insertions were implemented, plus a separate analysis for RPS17 because of its duplicate status. Mutation validation was by Sanger sequencing on an ABI Methods The coordinates for all 80 RP genes were used to generate custom SureSelect hybridisation capture baits via the Agilent web portal. 3µg DNA was extracted from 20 PB samples (including 2 controls with known mutations; 6 members from 3 family groups: a mother-daughter pair, a sibling pair and another sibling pair where one sibling was non-DBA and included as a control). Covaris sonication was performed and the DNA fragments were hybridised with the capture baits for 48h. After barcoded adapter ligation, the libraries were quantitated by qPCR and pooled into 2 runs of 10. The sequencing was performed on an Illumina MiSeq using 150bp paired-end chemistry. The reads were aligned to the hg19 reference using BWA and the variant calls made using GATK; ANNOVAR was used for functional annotations of the variants. Pipelines for both SNVs/indels and large deletions/insertions were implemented, plus a separate analysis for RPS17 because of its duplicate status. Mutation validation was by Sanger sequencing on an ABI The authors confirm that there are no relevant conflicts of interest to disclose TABLE 1. Gene variations flagged as loss of function and validated by Sanger sequencing.

7 Data now in press…

8

9 10 Identified DBA associated RP Genes = 7 genes in current molecular screen Mutations are mostly SNVs and indels, but large deletions & insertion are also seen

10 Why Screen? Accurate diagnosis Reproductive counselling Exclude silent DBA from related BMT donors Establish Genotype-Phenotype link Elucidate pathophysiology

11 Peripheral Blood Extract DNA RPS19 RPL5 RPL11 RPS24 RPS17 RPL35a RPS7 Current DBA Screening Pipeline Measure & QC Sanger Sequence PCR target gene exons

12 Why Next Gen Seq (NGS)? Very high throughput Can look at all +80 targets at once Can multiplex many samples at once Potential to pick up large (allele-loss) deletions & insertions Cost effective per-gene / per-sample

13 Next Generation Sequencing Workflow Genomic DNA 10 patient-parent pairs Fragment DNA Library quant, pool, clean up and cluster generation High-throughput Sequencing Data analysis Sanger seq validation Hybridise and capture Ribosomal Protein Gene DNA including exons, introns, & regulatory regions Target Enrichment

14 Results Summary SG= Stop Gain SNV (Nonsense); FSD= Frame-shift Deletion; FSI= Frame-shift Insertion; SL= Start Loss SNV (Missense); SSD= Splice Site Defect

15 Next Steps….. Agilent Haloplex Capture Ion Torrent High Throughput Seq Optimise NGS for upfront DBA screening + MLPA Assay for validation of large deletions

16

17 o 70% of cases now have a known genetic basis o Cellular models have shown deficiency of RPS19 leads to a defect in erythroid differentiation o Thought to be between the CFU- e and proerythroblast stage

18  Difficult to undertake DBA studies due to the rarity of the disease and thus difficulties in obtaining sufficient samples Therefore….  Stage of maturation is poorly characterised  Struggle to make a diagnosis morphologically  Cell morphology in the myeloid, lymphoid and megakaryocytic cell lineages is poorly documented St Marys Hospital London has the largest cohort of DBA patients worldwide

19 72 DBA patients currently registered at St Mary’s Hospital 31 patients have had a bone marrow aspirate 29 samples suitable for analysis (n=29) 10 normal paediatric controls

20  500 cell differential count  500 cell myeloid:erythroid differential conducted blind  50 megakaryocyte assessment also conducted blind

21 Reduced erythrocyte % in DBA patients

22 The Erythroid Lineage

23 Non lobulated Normal lobulation

24

25  Significant reductions in the erythroid lineage in concordance with DBA diagnosis  Demonstrated a stage of erythroid maturation arrest at the level of the proerythroblast  RPL5/RPL11 positive patients have a greater proportion of hypolobulated and non lobulated megakaryocytes

26

27

28 Next steps…………. Registry Genomewide approach Whole bone marrow study


Download ppt "Research in DBA? Josu de la Fuente St Mary’s Hospital Imperial College London."

Similar presentations


Ads by Google